Current Medical Guidelines for Exercise During Pregnancy
By Cara McDougall, Reg. PT
Traditional medical advice has been for exercising women to reduce their habitual levels of exertion during pregnancy and for non-exercising women to refrain from initiating strenuous exercise programs. This advice was based on concerns that exercise could negatively affect early pregnancy outcomes by increasing core body temperature leading to disturbances in growth , potential maternal musculoskeletal injury, or neonatal injury due to blunt trauma(1).
However, more current research that has focused on both aerobic and strength-conditioning exercise regimens during pregnancy has shown no increase in early pregnancy loss, late pregnancy complications, abnormal fetal growth , adverse neonatal outcomes (1,2) or preterm delivery (3).
Currently, the Society of Obstetricians and Gynecologists of Canada state that ” All women without contraindications should be encouraged to participate in aerobic and strength-conditioning exercises as part of a healthy lifestyle during pregnancy.” They go on to state, powerfully, that “Women and their care providers should consider the risks of NOT participating in exercise activities during pregnancy , including loss of muscular and cardiovascular fitness, excessive maternal weight gain, higher risk of gestational diabetes or pregnancy induced hypertension, development of varicose veins and deep vein thrombosis, a higher incidence of physical complaints sch as dyspnea or lower back pain, and poor psychological adjustment to the physical changes of pregnancy.”(1)
Therefore, one can deduce that the potential benefits of exercise are numerous and include, but are not limited to, improved aerobic and muscular fitness, promotion of appropriate weight gain, facilitation of labour, prevention of gestational glucose intolerance, prevention of pregnancy -induced hypertension, and improved symptoms of depression (4).
Despite the many benefits of exercise for the vast majority of pregnant women, its a good idea for both active and non-active women alike to be screened for appropriate physical activity when they become pregnant. The PARmed-X is a form that was developed by the Canadian Society for Exercise Physiology based on guidelines set forth by the Society of Obstetricians and Gynecologists and serves as both a medical clearance form and an educational handout. The pregnant woman is responsible for filling out the first page regarding her general health status and activity habits. In particular, this section screens for complications in previous pregnancies, as well as current risk factors including unexplained fainting or dizziness, vaginal bleeding, unexplained abdominal pain, sudden swelling in hands or ankles, etc. Then the woman’s healthcare provider completes a portion that lists both absolute and relative contraindications to exercise. This form is also a great resource for moms-to-be, as it includes exercise guidelines, suggestions of exercises that are particularly important for her changing body, as well as safety considerations.
Absolute contraindications to exercise during pregnancy include ruptured membranes, premature labour, persistent bleeding, placenta previa, incompetent cervix, evidence of intrauterine growth restriction, higher order pregnancy (meaning triplets or more), uncontrolled type 1 diabetes, hypertension, thyroid disease or other uncontrolled disease. Relative contraindications to exercise include history of spontaneous abortion or premature labour in previous pregnancies, mild to moderate cardiovascular or respiratory disease, anemia or iron deficiency, malnutrition or presence of an eating disorder, twin pregnancy after the 28th week, or other significant medical conditions (1).
In the absence of any absolute or relative contraindications to exercise , the FITT principles set forth by the Canadian Society for Exercise Physiology and the Society of Obstetricians and Gynecologists of Canada can provide some guidance regarding exercise prescription. In general it is recommended that pregnant women engage in cardiovascular or aerobic exercise 3-4 times per week at an intensity of 12-14 on the Borg rating of preceived exertion Scale which is described as “somewhat hard” on a continuum from no exertion at all at level 6 to maximal exertion at level 20. Alternatively, moms-to-be can use the simple talk test, which suggests that they be able to maintain a conversation at all times while working out. If the woman is just beginning an aerobic exercise regime, she is recommended to start at a duration of 15 minutes and slowly progress to 30 minutes, as tolerated. Obviously it is important for her to consider safety while keeping in mind the changes to her posture and balance, as well as the physical environment around her and the likelihood of injury, when choosing an appropriate form of cardiovascular exercise.
Besides, aerobic exercise, pregnant women are also recommended to engage in strength-conditioning exercises at a frequency of 2-3x/wk, and at the same level of intensity as cardiovascular exercise. The prescription for reps and sets is 10-15 and 1-3 respectively, not unlike general strength training recommendations. Suggested strengthening exercises include large muscle groups and functional movement patterns. Some examples include rows for enhancing scapular and postural muscles, biceps for lifting and and carrying the baby, and quads and glutes for repeated squatting and bending.
With regard to flexibility exercises, which can be done daily at a gentle intensity, and held for 30-60 sec, particularly important exercises are those that help to correct common but non-optimal postures observed in pregnant women, such as protracted shoulders, increased thoracic kyphosis, and increased lumber lordosis. Some examples to counteract this commonly seen posture include pec, glute and hip flexor stretches (1).
the American and Canadian Societies for Exercise Physiology advocate that pregnant women participate in particular activities that they deem safe relative to others, determined primarily on the basis of the potential for loss of balance, as well as risk of impact such as in contact sports. Thus, their list of safe activities includes walking, swimming, aqua fit, stationary cycling, low impact aerobics, yoga, pilates, cross-country skiing, jogging, racquet sports, and strength training. On the other hand, they deem unsafe sports to include contact sports such as hockey, boxing, soccer, and basketball, activities that have a high risk of falling, such as downhill or water skiing, surfing, off road cycling, gymnastics, and horseback riding. They also warn pregnant women to refrain from doing hot yoga or pilates, scuba diving, and sky diving.
Further general safety considerations include avoiding exercising in hot or humid environments, avoiding isometric exercise or straining while breath holding, maintaining adequate nutrition and hydration, and avoiding exercise in supine past the fourth month of gestation (2).
While these guidelines are appropriate for the majority of pregnant women, especially those starting to become active during pregnancy, it should be noted that exercise prescription must still be made on an individualized basis.
Although the benefits of exercise during pregnancy are now widely accepted, if a women experiences certain symptoms while exercising, it may be necessary for her to stop and seek medical attention. These symptoms may include, but are not limited to, excessive shortness of breath, chest pain, presyncope, painful uterine contractions, leakage of amniotic fluid, vaginal bleeding, or decreased fetal movement (1,5).
In summary, despite the fact that pregnancy is associated with vast anatomical and physiological changes, exercise has minimal risks and known benefits. If you are pregnant and have any questions about appropriate exercise prescription, book yourself in to see a pelvic floor physiotherapist today!
Also, stay tuned for our follow up blog still to come on ‘Do’s, Don’ts and Dispelling Myths About Exercise During Pregnancy’.
REFERENCES
1. Davies G, Wolf l, Mottoba M, MacKinnon C, Joint SOGC/CSEP Clinical Practice Guideline: Exercise in pregnancy and the postpartum period. Canadian Journal of Applied Physiology 2003, 28(3): 329-341.
2. Physical activity and exercises during pregnancy and the postpartum period. Committee Opinion No. 650. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;126:e135-42.
3. Barakat R, Pelaez M, Montejo R, Refoyo I, Coteron J. Exercise throughout pregnancy does not cause preterm delivery: a randomized, controlled trial. J Phys act Health 2014;11:1012-7.
4. Nasciment S, Surita F, Cecatti J. Physical exercise during pregnancy : a systematic review. Curr Opin Obstet Gynecol 2012, 24:387-394.
5. Artal R, O’Toole M. Guidelines of the American Colleg of Obstetricians and Gynecologists for exercise during pregnancy and the postpartum period . Br J Sports Med 2003;37:6-12.